Boost Serialization library provides a great solution for serializing derived classes by pointers to base classes, but I'm concerned with a simple use case: The program is being used on two computers "A" and "B" where "A" sends data to "B" by the means of serialization. At some upgrade of the program a serialized class "bus" is complemented with a derived class "big_bus". Only computer "A" gets the new version. I don't want the old version on "B" to dismiss a received "big_bus" object from "A", I need to convert it into a "bus" class object. It is sometimes much more useful to process the "big_bus" as a "bus" than not to process at all. I can assure serialization of each derivation starts with the serialization of the base class. I'm also ready to cope with the overhead of storing parent class information within the information about the derived classes. And it's ok if multiple inheritance is out of the question. Is there a pattern, a proposed solution to allow this dynamic "fallback" to base classes?